How does the text describe the Guru's relationship to Brahman and the transient world, and what path should a disciple follow based on this understanding?

The text presents a clear philosophical framework in Chapter 45, stating that Brahman is eternal while the world is transient. Crucially, it identifies the Guru alone as the true Brahman, a "solid mass of Brahman-consciousness." Based on this understanding, the path for a disciple is to practice discrimination between the eternal (the Guru) and the transient (the world). This involves renouncing the transient, which leads to the birth of dispassion, or Vairagya. The disciple should then meditate exclusively on the Guru. This constancy of feeling is described as the means to achieve the spiritual goal and leads to a state of "undifferentiated worship" (Abheda-bhajan), where divinity is perceived in all beings.